perf_counter/powerpc: Check oprofile_cpu_type for NULL before using it

If the current CPU doesn't support performance counters,
cur_cpu_spec->oprofile_cpu_type can be NULL. The current
perf_counter modules don't test for that case and would thus
crash at boot time.

Bug reported by David Woodhouse.

Reported-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul Mackerras <paulus@samba.org>
LKML-Reference: <19066.48028.446975.501454@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

7 files changed, 16 insertions, 9 deletions

diff --git a/arch/powerpc/kernel/mpc7450-pmu.c b/arch/powerpc/kernel/mpc7450-pmu.c
index c244133c67a6..cc466d039af6 100644
--- a/arch/powerpc/kernel/mpc7450-pmu.c
+++ b/arch/powerpc/kernel/mpc7450-pmu.c
@@ -407,7 +407,8 @@ struct power_pmu mpc7450_pmu = {
 
 static int init_mpc7450_pmu(void)
 {
-	if (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc/7450"))
+	if (!cur_cpu_spec->oprofile_cpu_type ||
+	    strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc/7450"))
 		return -ENODEV;
 
 	return register_power_pmu(&mpc7450_pmu);
diff --git a/arch/powerpc/kernel/power4-pmu.c b/arch/powerpc/kernel/power4-pmu.c
index db90b0c5c27b..3c90a3d9173e 100644
--- a/arch/powerpc/kernel/power4-pmu.c
+++ b/arch/powerpc/kernel/power4-pmu.c
@@ -606,7 +606,8 @@ static struct power_pmu power4_pmu = {
 
 static int init_power4_pmu(void)
 {
-	if (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power4"))
+	if (!cur_cpu_spec->oprofile_cpu_type ||
+	    strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power4"))
 		return -ENODEV;
 
 	return register_power_pmu(&power4_pmu);
diff --git a/arch/powerpc/kernel/power5+-pmu.c b/arch/powerpc/kernel/power5+-pmu.c
index f4adca8e98a4..31918af3e355 100644
--- a/arch/powerpc/kernel/power5+-pmu.c
+++ b/arch/powerpc/kernel/power5+-pmu.c
@@ -678,8 +678,9 @@ static struct power_pmu power5p_pmu = {
 
 static int init_power5p_pmu(void)
 {
-	if (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power5+")
-	    && strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power5++"))
+	if (!cur_cpu_spec->oprofile_cpu_type ||
+	    (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power5+")
+	     && strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power5++")))
 		return -ENODEV;
 
 	return register_power_pmu(&power5p_pmu);
diff --git a/arch/powerpc/kernel/power5-pmu.c b/arch/powerpc/kernel/power5-pmu.c
index 29b2c6c0e83a..867f6f663963 100644
--- a/arch/powerpc/kernel/power5-pmu.c
+++ b/arch/powerpc/kernel/power5-pmu.c
@@ -618,7 +618,8 @@ static struct power_pmu power5_pmu = {
 
 static int init_power5_pmu(void)
 {
-	if (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power5"))
+	if (!cur_cpu_spec->oprofile_cpu_type ||
+	    strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power5"))
 		return -ENODEV;
 
 	return register_power_pmu(&power5_pmu);
diff --git a/arch/powerpc/kernel/power6-pmu.c b/arch/powerpc/kernel/power6-pmu.c
index 09ae5bf5bda7..fa21890531da 100644
--- a/arch/powerpc/kernel/power6-pmu.c
+++ b/arch/powerpc/kernel/power6-pmu.c
@@ -537,7 +537,8 @@ static struct power_pmu power6_pmu = {
 
 static int init_power6_pmu(void)
 {
-	if (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power6"))
+	if (!cur_cpu_spec->oprofile_cpu_type ||
+	    strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power6"))
 		return -ENODEV;
 
 	return register_power_pmu(&power6_pmu);
diff --git a/arch/powerpc/kernel/power7-pmu.c b/arch/powerpc/kernel/power7-pmu.c
index 5a9f5cbd40a4..388cf57ad827 100644
--- a/arch/powerpc/kernel/power7-pmu.c
+++ b/arch/powerpc/kernel/power7-pmu.c
@@ -366,7 +366,8 @@ static struct power_pmu power7_pmu = {
 
 static int init_power7_pmu(void)
 {
-	if (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power7"))
+	if (!cur_cpu_spec->oprofile_cpu_type ||
+	    strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power7"))
 		return -ENODEV;
 
 	return register_power_pmu(&power7_pmu);
diff --git a/arch/powerpc/kernel/ppc970-pmu.c b/arch/powerpc/kernel/ppc970-pmu.c
index 833097ac45dc..75dccb71a043 100644
--- a/arch/powerpc/kernel/ppc970-pmu.c
+++ b/arch/powerpc/kernel/ppc970-pmu.c
@@ -488,8 +488,9 @@ static struct power_pmu ppc970_pmu = {
 
 static int init_ppc970_pmu(void)
 {
-	if (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/970")
-	    && strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/970MP"))
+	if (!cur_cpu_spec->oprofile_cpu_type ||
+	    (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/970")
+	     && strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/970MP")))
 		return -ENODEV;
 
 	return register_power_pmu(&ppc970_pmu);